Cutting mechanism for knitting machines



Feb. 21, 1950 J. H. SCHAEFER, JR 2,498,09fi

CUTTING MECHANISM FOR KNITTING MACHINES Filed ma 'z'r, 1948 2 Sheets-Sheet 1 BY WW A TTORNE YS.

Feb, 21, 1951) J. H. SCHAEFER, JR

CUTTING MECHANISM FOR KNITTING MACHINES 2 Sheets-She et 2 Filed May 27, 1948 INVENTOR: Jahnflezzlydcfiwigfi, BY WW WITNESSES 0d g c3 ATTORNEYS.

Patented Feb. 21, 1950 CUTTING MECHANISM FOR KNITTING MACHINES John Henry Schaefer, J12, Boyertown, Pa., as-

signor to The Vaughan Knitting Company, I nc., Pottstown, Pa, a corporation of Pennsylvania Application May 27, 1948, Serial No. 29,497

10 Claims.

This invention relates to cutting mechanism for knitting machines. More specifically it is concerned with a cutting mechanism useful with circular knitting machines of any of the well known commercial types which continually produce stocking blanks or the like in succession in string form with segments of one of the yarns, which may for example be a warp striping yarn, connecting the contiguous blanks of the strings. In order to separate the individual blanks from the strings, it has heretofore been necessary for the machine attendants to sever or break the connecting thread segments by hand. This was not only an awkward task by reason of the relative inaccessibility to the string as it immerged beneath the needle cylinders of the machines, but time consuming as well, requiring the attendants to be constantly alert and detracting from their performance of other more important duties.

The chief aim of my invention is to obviate the above drawbacks. This desideratum is realized in practice, as hereinafter more fully disclosed, through provision of a simple and reliable cutting mechanism in the form of an attachment which can be readily incorporated in any existent circular knitting machine of the kind mentioned at small expense and without requiring any structural alterations in the machines or modification in their usual mode of operation, and which is arranged to be automatically actuated through motion derived from a rotating part of the machine mechanisms, during each blank knitting A cycle to sever the thread segment between contiguous blanks of the string.

Other objects and advantages will appear from the following detailed description of the attached drawings wherein Fig. 1 is a fragmentary view in side elevation of a portion of a standard circular knitting machine fitted with my improved cutting mechanism.

Fig. 2 is a fragmentary horizontal section taken as indicated by the angled arrows II-II in Fig. 1.

Fig. 3 is a fragmentary view in vertical section taken as indicated by the angled arrows III-III in Fig. 2, and

Fig. 4 is a view like Fig. 2 showing how a connecting thread segment between contiguous blanks of the string produced by the machine is severed in accordance with my invention.

As herein shown, my improved cutting mechanism comprises a slide bar 5 which is constrained to endwise movement radially of the delivery sleeve 6 through which the string of blanks indicated at B descends from a needle cylinder, (not shown) of the machine, in the lengthwise groove 2 l of a guide 8. At 9 is indicated one of the side frames of the machine wherefrom extends a bracket H! to which the guide block 8 is rigidly secured. Affixed to the top of the slide bar 5 is the ledger blade II of a severing device whereof the movable opposing blade I2 is pivoted on a stud l3 upstanding from said bar. Normally, the movable blade 92 of thissevering device is yieldingly held in open position, with the slide bar 5 fully retracted, against a projection M on an auxiliary slide l5, by a spring lZa. As shown, the axuiliary slide I5 is in turn constrained to endwise movement in a second guide Way It formed in a laterally offset portion 8a of the guide 8 in parallel relation to the groove 1. The auxiliary slide it is subject to the pull of a spring Ill, and its movement in one direction is limited by contact of the projection l4 thereon with a cap plate l8 secured to the top of the guide 8, and in the other direction by engagement of a stop I!) at its outer end with said plate l8. The projection l4 on the auxiliary slide [5 provides a beveled cam surface Ma to react, in the manner later on explained, with a roller 20 on the movable shearing blade l2. The slide bar 5 is arranged to be actuated through engagement of a roller 2| at its outer end, by one end of a lever 22 which is medially fulcrummed at 23 on a bracket arm extension 24 of the guide 8. At its opposite end, the lever 22 carries a roller cam rise 26 on the outer side face of a standard cam drum 21 of the machine. As usual this drum 2? is mounted on one end of a shaft 28 which is rotatively borne in the side frame 9 and which is intermittently racked through a complete revolution during each blank knitting cycle of the machine.

To the pendent sleeve 6 of the needle cylinder (not shown) of the machine to extend downward therefrom in coaxial relation is a supplemental tubular delivery extension 30. As shown in Fig. 3, the upper end of the supplemental tube 30 is so shaped as to provide an opening at 3| for entry of the severing device. Secured within the tube 30 opposite the opening 3| in accordance with my invention, is a downwardly and forwardly inclined tongue 32 by which the connecting thread segments T are successively deflected toward the severing device and at the same time braced against displacement upon approach thereto of said device in the manner presently explained.

Operation At the termination of each blank knitting cycle, the drum 21 is given a final rotative shift to bring 25 in the path of a the special cam projection 26 thereon into engagement with the roller 25 on the lever 22, this action occurring when the thread segment T connecting contiguous blanks B of the string arrives at the deflecting tongue 32 as shown in Fig. 3. By actuation of the lever 22, the slide is shifted in the direction of the arrow in Fig. 2 against the pull of spring [26; as far as permitted by engagement of a stop 33 at the bottom of said slide with the guide block 8 as shown in Fig. 4, and the severing means thrust inward through the opening 3! in tube 30. During the latter part of the thrust, the roller 20 on the movable blade 12 contacts the cam projection I 4 on the auxiliary slide (5 whereby the latter is carried along with the slide 5. Eventually, the movement of the auxiliary slide [5 is interrupted by contact of the stop l9 thereon with the cap plate 13, whereupon,

as the stroke is completed, the cam surface 4a on the projection reacts with the roller 29 to close the movable blad I 2 .upon the ledger blade H to sever the thread segment T as shown in Fig. 4, displacement of said segment being prevented to insure its being cut, by the bracing action of the tongue 32 as inFig. 3. Upon passage of the cam projection 2.6 on the drum 21 beyond the roller 25 on the lever 22, the parts of the cutting mechanism are all automatically restored to the normal positions in which they are illustrated in Figs. 1 and 2 by the springs I20. and H.

Having thus described my invention, I claim:

1. Cutting mechanism for a circular knitting machine which continually produces astring of ind'vidually pressed-on" stocking blanks or the like in succession with one blank connected to the next by a longitudinallyextending segment of one of the knitting threads, said mechanism including a severing device; means forsupporting the severing devicein-a normally retracted position out of the path of the stringof blanks coming from the machine; and means actuated during each blank knitting cycle to advance the severing device into cutting position in the interval between a contiguous pair of theblanks of the string and incidentally operate it to sever the thread segment connecting the blanks of such pair.

2. Cutting mechanism according to claim 1, further including means for holding the thread segment against displacement in the path of the severing means during advance of the latter to cutting position. i

3. Cutting mechanism for a circular knitting machine which continually produces a string of stocking blanks or the like in succession with one blank connected to the next by a segment of one of the knitting threads, and which has a vertical delivery tube through which the string of blanks descends, said mechanism including a severing device; means for supporting the severing device in a normally retracted position out of the path of the string of blanks as it comes from the machine; and means actuated during each blank kmttinglcycle of the machine for thrusting the severing device into cutting position through a lateral clearance opening in the delivery tube aforesaid, and for incidently operating it to sever the threadse'gment connecting a contiguous pair of blanks in the string. 4. Cutting mechanism according to claim 3, further including means within the delivery tube for engaging the connecting thread segment between each pair of contiguous blanks in the string and hold it against displacement as the severing device is thruet intocutting'position to effect the ggvgy gg 5. A cutting device according to claim 3, further including a deflecting element within the delivery tube, said element being in the form of a tongue inclined forwardly and downwardly toward the lateral opening in the tube, for holding the connecting thread segment between each pair of contiguous blanks in the string against displacement as the severing device is thrust inward to cutting position through said opening to effect the severing.

6. Cutting mechanism for a circular knitting machine which continually produces a string of stocking blanks or the like in succession with one blank connected to the next by a longitudinallyextending segment of one of the knitting threads, and which has a cam drum moved through a complete rotation during each blank knitting cycle, said mechanism including a severing device; means for supporting the severing device in a normally retracted position out of the path of the string of blanks; and means controlled from the aforesaid cam drum during each rotation thereor for advancing the shearing device into cutting position in the interval between a pair of successive blanks of the string and for actuating it to sever the thread segment connecting the blanks of such pair.

'7. Cutting mechanism for a knitting machine which continually produces a string of stocking blanks or the like in succession with one blank connected to the next by a short longitudinallyextending segment of one of the knitting threads; said mechanism including a severing device with relatively movable opposing cutting blades; means for supporting the severing device, with its blades open, in a normally retracted position out of the path of the blank string coming from the machine; and means actuated during each blank knitting cycle of the machine 'for advancing the severing device into cutting position in the interval between a pair of contiguous blanks of the string and for incidently closing its blades to sever a thread segment connecting the blanks of such pair.

8. Cutting mechanism for a circular knitting machine which continually produces a string of stocking blanks or the like in succession with one blank connected to the next by a segment of one of the yarns used in the knitting, and which has a vertical delivery tube through which the string of blanks descends, said mechanism including a slide, a severing device with a ledger blade afiixed to the slide and an opposing cutting blade pivoted on the slide; a guide in which the slide is constrained to movement radially of the delivery tube; means actuated during each blank knitting cycle of the machine to move the slide and thereby thrust the severing means from 2. normally retracted position with the blades open, through a lateral clearance opening in said delivery tube, to cutting position within the latter; and means for incidently operating the movable cutting blade to sever a yarn segment connecting a contiguous pair of blanks in the string.

9. Cutting mechanism according to claim 8, wherein the means for operating the movable cutting blade includes a cam along the path of the severing device, and a roller on said movable blade to react with said cam.

10. Cutting mechanism according to claim 8, wherein the means for operating the movable cutting blade includes a cam along the path of the severing device, a'rollcr on said movable blade to react with the cam, and an auxiliary supporting slide forthe cam arranged to move partway with the ledger blade carrying slide in parallel relation thereto during the inward thrust of the severing device to cutting position.

JOHN HENRY SCHAEFER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Raven Dec. 31, 1912 Ryan Mar. 18, 1913 Lawson Sept. 29, 1914 Campbell Jan. 27, 1925 Schilke May 13, 1941 

